They were a real hazard. Sharp bits of metal scattered all over the place.

People would pull them off and drop them in the can before drinking. That I remember seeing myself. Then I saw an episode of Emergency where a guy did that and ended up drinking the pull tab. It got stuck in his throat. Who knows if that was based on truth, but scared me so much that I would tell anyone and everyone not to put the tab into the can until after the can was empty.